Giant mulch pile bursts into flames on the Mattapan/Roslindale line

Deep enough piles of mulch left sitting long enough can spontaneously catch fire. (PDF) Since this usually happens in the very middle of the pile, it's tough to put it out by spraying water on the outside. The landscaper should know all that.

My neighbor’s yard caught fire twice one summer. Fire trucks needed both times.

of burning decomposing organic matter. Motion to name this the official mascot of 2020?

Can it be seen from space?

Once many years ago, I was in Ireland on vacation, catching up on family roots.

It was July or August, and had been unusually hot and dry for that area, especially for the previous month. I was out with my uncle, and we stopped at one country cemetery to make a visit to the family plot. As we walked up the hill from the car park, we came to a grave that had smoke rising from it!
My uncle concluded that peat had gotten mixed with clean fill at some point, and with the heat and dry weather had started to combust. Entirely reasonable, rational analysis - but the sight of it was still enough to give one pause.
Uncle found a communal bucket or watering can, filled it at a spigot, and a couple of trips was enough to douse the grave.

Anaerobic bacteria is amazing stuff. In my landscaping days, I always remembered piles of mulch that steamed when you stuck a pitchfork into them--surprising heat. Mulch spread out, when its got more exposed surface area, is pretty benign. Large piles, however, have minds of their own.

On a side note, haystacks are also prone to spontaneous combustion for the same reason.

Why don't they just make 2 smaller piles? There is room in that paddock.

The right combination of carbon, nitrogen, water in proper quantities equals heat potentially rising to fire. Basic fun science.

Adding water can actually increase the fire potential by providing increasing the bacterial activity.

With enough coffee grinds, water and last year's leaves can make for a 180 degree 5x5x3 compost pile. I measured it one year when I realized a roommate was adding massive amounts of coffee grinds.

It is science and still seems pretty darn magical.

Also, engine trucks have to line up to relay water from a hydrant; the pile itself has no nearby hydrants

A few questions...

What is the code-allowed maximum distance to a hydrant? What is the preferred maximum distance? How far can one fire truck set up a relay connection (since the article says trucks plural were needed)?

Boston hydrant map shows a hydrant on this property, maybe 250-300 feet from the pile. Is that map wrong? Was the hydrant out of service? Was the hydrant blocked?

This business accepts yard waste from landscapers for a fee. In this streetview you can see a large pile of something with obvious brown paper leaf bags in the front. Isn't this pile really more of a recycling landfill than true bark mulch? Do they have a permit to run such a business?

https://goo.gl/maps/Ewv3f3VWeLvW3hkX7